The role of alcohol in infant cosleeping deaths

The well-established epidemiological and neuropathological differences between infants who die alone compared to those in shared sleeping environments indicate that these cohorts have differences. Risk factors in both situations depend on both exogenous and endogenous factors. Although parental consumption of alcohol continues to be cited as a risk factor for sudden infant death syndrome (SIDS) it is difficult to understand how a substance which impairs parental consciousness rather than infant arousal could contribute to SIDS. Surely a more logical mechanism to explain these deaths would be suffocation by a sedated adult rather than evoking predisposing factors for SIDS.

Prenatal and postnatal factors associated with sudden infant death syndrome: an umbrella review of meta-analyses

BACKGROUND

Comprehensive quantitative evidence on the risk and protective factors for sudden infant death syndrome (SIDS) effects is lacking. We investigated the risk and protective factors related to SIDS.

METHODS

We conducted an umbrella review of meta-analyses of observational and interventional studies assessing SIDS-related factors. PubMed/MEDLINE, Embase, EBSCO, and Google Scholar were searched from inception until January 18, 2023. Data extraction, quality assessment, and certainty of evidence were assessed by using A Measurement Tool Assessment Systematic Reviews 2 following PRISMA guidelines. According to observational evidence, credibility was graded and classified by class and quality of evidence (CE; convincing, highly suggestive, suggestive, weak, or not significant). Our study protocol was registered with PROSPERO (CRD42023458696). The risk and protective factors related to SIDS are presented as equivalent odds ratios (eORs).

RESULTS

We identified eight original meta-analyses, including 152 original articles, covering 12 unique risk and protective factors for SIDS across 21 countries/regions and five continents. Several risk factors, including prenatal drug exposure [eOR = 7.84 (95% CI = 4.81-12.79), CE = highly suggestive], prenatal opioid exposure [9.55 (95% CI = 4.87-18.72), CE = suggestive], prenatal methadone exposure [9.52 (95% CI = 3.34-27.10), CE = weak], prenatal cocaine exposure [4.38 (95% CI = 1.95-9.86), CE = weak], prenatal maternal smoking [2.25 (95% CI = 1.95-2.60), CE = highly suggestive], postnatal maternal smoking [1.97 (95% CI = 1.75-2.22), CE = weak], bed sharing [2.89 (95% CI = 1.81-4.60), CE = weak], and infants found with heads covered by bedclothes after last sleep [11.01 (95% CI = 5.40-22.45), CE = suggestive], were identified. On the other hand, three protective factors, namely, breastfeeding [0.57 (95% CI = 0.39-0.83), CE = non-significant], supine sleeping position [0.48 (95% CI = 0.37-0.63), CE = suggestive], and pacifier use [0.44 (95% CI = 0.30-0.65), CE = weak], were also identified.

CONCLUSIONS

Based on the evidence, we propose several risk and protective factors for SIDS. This study suggests the need for further studies on SIDS-related factors supported by weak credibility, no association, or a lack of adequate research.

The role of pathologists in increasing knowledge of safe sleep practices for infants

Recent studies have evaluated parental knowledge of safe sleeping practices for their infants by using follow-up questionnaires at postnatal obstetric clinic visits. While many parents increase their knowledge of the key features of safe sleeping during antenatal visits, a significant number subsequently fail to adhere to guidelines. An additional way to assess parental understanding of safe and unsafe sleeping practices may be to incorporate information from pathological evaluations of infants who do not survive. Specifically, information from careful investigations of death scenes and meticulous autopsy examinations may be a useful way to complement clinical surveys so that the chances of assisting parents in future with their understanding of safe infant sleep practices will be maximised.

Brain water content in sudden unexpected infant death

The extensive and rapid development of the human brain during the first years of life complicates the postmortem diagnosis of brain edema in infancy. The aim of this study was to describe brain water content, the brain weight/body weight ratio, and the brain weight/head circumference ratio throughout the first years of life. Furthermore, we examined the relationship between these parameters and rs2075575 in the AQP4 gene. Our hypothesis was that dysregulated water homeostasis might be a risk factor for sudden infant death syndrome (SIDS), which may be reflected by increased water content in the brain. The study included 90 subjects with sudden unexpected death < 4 years of age: 22 cases of sudden infant death syndrome, 11 cases of sudden unexplained death in childhood, 47 cases of death due to disease, and 10 cases of accident/violent death. Brain water content, brain weight/body weight ratio, and brain weight/head circumference ratio were investigated according to corrected age, diagnosis group, attempt to resuscitate, and presence of brain edema. We found that brain water content and brain weight/body weight ratio were significantly reduced with increasing age, while brain weight/head circumference were increased. Brain weight/head circumference was correlated with brain water content. Cases with brain edema had a significantly higher brain weight/head circumference than the non-edematous cases. No differences were found between the diagnosis groups for any of the investigated parameters. In summary, the findings contribute to the current body of knowledge regarding brain growth during the first months of life.

Steering the Titanic: One tertiary care children's hospital's experience navigating safe sleep for hospitalized infants

BACKGROUND

Sudden Unexpected Infant Death (SUID) is the leading cause of death in infants 1 month to 1 year of age in the United States. Despite extensive efforts in research and public education, rates of sleep-related infant death have plateaued since the late-1990s, largely due to unsafe sleep practices and environments.

LOCAL PROBLEM

A multidisciplinary team assessed our institution's compliance with its own infant safe sleep policy. Data was collected on infant sleep practices, nurses' knowledge and training on the hospital policy, and teaching practices for parents and caregivers of hospitalized infants. Zero crib environments from our baseline observation met all the American Academy of Pediatrics recommendations for infant safe sleep.

METHODS

A comprehensive safe sleep program was implemented in a large pediatric hospital system. The purpose of this quality improvement project was to improve compliance with safe sleep practice from 0% to 80%, documentation of infant sleep position and environment every shift from 0% to 90%, and documentation of caregiver education from 12% to 90% within 24 months.

INTERVENTIONS

Interventions included revision of hospital policy, staff education, family education, environmental modifications, creation of a safe sleep taskforce, and electronic health record modifications.

RESULTS

Documented compliance with infant safe sleep interventions at the bedside improved from 0% to 88%, while documentation of family safe sleep education improved from 12% to 97% during the study period.

CONCLUSIONS

A multifaceted, multidisciplinary approach can lead to significant improvements in infant safe sleep practices and education in a large tertiary care children's hospital system.

Pre- and postnatal safe sleep knowledge and planned as compared to actual infant sleep practices

BACKGROUND

Our objectives were to compare safe sleep knowledge, attitudes and planned vs. actual infant sleep practices among expectant mothers before and after their infant's birth and to determine whether differences (if present) were associated with any demographic variables.

METHODS

Study participants were surveyed at their 28-week prenatal and 6-week postpartum obstetric clinic visits from November 2019-February 2021. Due to COVID-19 pandemic cancellation of in-person postpartum visits, many participants received text messaging encouraging them to take the follow-up survey online. Frequency and comparative analyses were performed.

RESULTS

355 women (44%) completed both pre- and postnatal surveys. Many participants increased their safe sleep knowledge during the study. For example, of those who were unsure or thought it safe for a baby to sleep in a baby swing/bouncy seat, two-thirds (67/102, 66%) stated it was unsafe on the postnatal survey. In addition, many who were unsure or planned sleep practices considered unsafe prenatally reported utilizing safe sleep practices on their postnatal survey. For example, of those unsure or planning to use a crib bumper (17% of the total), almost all (88%) were not using one postnatally. Conversely, some participants who reported they would be following safe sleep practices prenatally were not doing so postpartum. For example, 13% of those stating they would place their child on their back reported using another sleep position on the postnatal survey. Certain demographics had higher proportions reporting this reversal for specific safe sleep practices. For example, non-Hispanic Whites (19%) as compared to other races/ethnicities (5%) and those with incomes ≥ $75,000 (21%) as compared with those with less income (9%) had higher proportions stating their infant would sleep in the same room but then reported postnatally they were sleeping in a different room, p = 0.0094 and p = 0.0138, respectively.

CONCLUSIONS

We observed increases in safe sleep knowledge and that some participants followed safer sleep practices than they had planned. However, there were also participants who planned to use safe sleep practices prenatally who were not doing so after their baby's birth. Our study identified demographics for which targeted safe sleep education and more effective interventions may be needed.

The diminishing role of the pathologist in sudden infant death syndrome

All major definitions of sudden infant death syndrome (SIDS) specify that a careful pathological examination must be conducted which includes performance of a "complete" autopsy. Unfortunately, there is an increasing trend for cases to be classified as SIDS without fulfilling the required criteria, even including cases where an autopsy has not been performed. Failure to have an experienced pathologist with an understanding of SIDS involved in every step of the investigation and follow-up, with or without subsequent studies, may severely undermine the veracity of the diagnosis and the reliability of subsequent research conclusions.

Carotid Body Dysfunction and Mechanisms of Disease

Emerging evidence shows that the carotid body (CB) dysfunction is implicated in various physiological and pathophysiological conditions. It has been revealed that the CB structure and neurochemical profile alter in certain human sympathetic-related and cardiometabolic diseases. Specifically, a tiny CB with a decrease of glomus cells and their dense-cored vesicles has been seen in subjects with sleep disordered breathing such as sudden infant death syndrome and obstructive sleep apnea patients and people with congenital central hypoventilation syndrome. Moreover, the CB degranulation is accompanied by significantly elevated levels of catecholamines and proinflammatory cytokines in such patients. The intermittent hypoxia stimulates the CB, eliciting augmented chemoreflex drive and enhanced cardiorespiratory and sympathetic responses. High CB excitability due to blood flow restrictions, oxidative stress, alterations in neurotransmitter gases and disruptions of local mediators is also observed in congestive heart failure conditions. On the other hand, the morpho-chemical changes in hypertension include an increase in the CB volume due to vasodilation, altered transmitter phenotype of chemoreceptor cells and elevated production of neurotrophic factors. Accordingly, in both humans and animal models CB denervation prevents the breathing instability and lowers blood pressure. Knowledge of the morphofunctional aspects of the CB, a better understanding of its role in disease and recent advances in human CB translational research would contribute to the development of new therapeutic strategies.

Genetic Determinants of Sudden Unexpected Death in Pediatrics

PURPOSE

This study aimed to evaluate genetic contributions to sudden unexpected death in pediatrics (SUDP).

METHODS

We phenotyped and performed exome sequencing for 352 SUDP cases. We analyzed variants in 294 "SUDP genes" with mechanisms plausibly related to sudden death. In a subset of 73 cases with parental data (trios), we performed exome-wide analyses and conducted cohort-wide burden analyses.

RESULTS

In total, we identified likely contributory variants in 37 of 352 probands (11%). Analysis of SUDP genes identified pathogenic/likely pathogenic variants in 12 of 352 cases (SCN1A, DEPDC5 [2], GABRG2, SCN5A [2], TTN [2], MYBPC3, PLN, TNNI3, and PDHA1) and variants of unknown significance-favor-pathogenic in 17 of 352 cases. Exome-wide analyses of the 73 cases with family data additionally identified 4 de novo pathogenic/likely pathogenic variants (SCN1A [2], ANKRD1, and BRPF1) and 4 de novo variants of unknown significance-favor-pathogenic. Comparing cases with controls, we demonstrated an excess burden of rare damaging SUDP gene variants (odds ratio, 2.94; 95% confidence interval, 2.37-4.21) and of exome-wide de novo variants in the subset of 73 with trio data (odds ratio, 3.13; 95% confidence interval, 1.91-5.16).

CONCLUSION

We provide strong evidence for a role of genetic factors in SUDP, involving both candidate genes and novel genes for SUDP and expanding phenotypes of disease genes not previously associated with sudden death.

Variations in Safe Sleep Practices and Beliefs: Knowledge is not Enough

OBJECTIVES

Sleep-related infant deaths in the District of Columbia (DC) varies, with rates in certain geographical areas three times higher than DC and seven times higher than the national average. We sought to understand differences in infant sleep knowledge, beliefs, and practices between families in high-risk infant mortality and low-risk infant mortality areas in DC.

METHODS

Caregivers of infants presenting to the emergency department were surveyed. The associations between location and safe sleep knowledge, beliefs, and practices were analyzed.

RESULTS

Two hundred and eighty-four caregivers were surveyed; 105 (37%) were from the high-risk infant mortality area. The majority (68%) of caregivers reported placing their infant to sleep on their backs, sleeping in a crib, bassinet, or pack and play (72%), and were familiar with the phrase "safe sleep" (72%). Caregivers from the high-risk infant mortality area were more likely to report that their infants sleep in homes other than their own (aOR 1.53; 95% CI 1.23, 2.81) and other people took care of their infants while sleeping (aOR 1.76; 95% CI 1.17, 3.19), adjusting for race/ethnicity, education, marital status, and help with childcare. No differences in safe sleep knowledge, beliefs, and practices were present.

CONCLUSIONS FOR PRACTICE

Infants from the high-risk infant mortality area were more likely to sleep in homes other than their own and have other caretakers while sleeping. Lack of differences in caregiver awareness of safe sleep recommendation or practices suggests effective safe sleep messaging. Outreach to other caregivers and study of unmet barriers is needed.

Physiological QT Interval Changes in Early Infancy Using Post-Menstrual and Post-Natal Age Calculation for Electrocardiogram Long QT Interval Screening in Taiwan

BACKGROUND

Prolongation of the QT interval is associated with the risk of sudden infant death syndrome. QT interval differs depending on age at the time of screening. Screening protocols have yet to be established for Taiwanese patients.

OBJECTIVES

To construct QT interval reference values during early infancy, to investigate whether QT interval change differs according to age calculation methods, and to identify an optimal QT correction method and associated infant factors.

METHODS

Electrocardiographic readings and QT intervals were recorded cross-sectionally in 595 healthy infants and screened prospectively for long QT interval. Corrected QT intervals with Bazett's (QTc-B) and Fridericia's (QTc-F) formulas were compared by post-natal and post-menstrual screening age, sex, body mass index (BMI), heart rate (HR), birth and family history.

RESULTS

QTc-B and QTc-F decreased in the second month (31-60 days), and peaked in the third month (61-90 days). QT interval length was similar between post-menstrual and post-natal ages for QTc-B. Simple linear regression showed that post-menstrual age, post-natal age, HR and BMI were associated with QTc-F, while only sex and HR were associated with QTc-B. Although both QTc-B and QTc-F were significantly associated with HR, QTc-B was less affected by HR than QTc-F (β = -0.1, p < 0.05 for QTc-B vs. β = -0.3, p < 0.001 for QTc-F). Female infants tended to have slightly longer QTc intervals.

CONCLUSIONS

QT interval in early infancy changed physiologically, peaking in the third month. The rate of QT change was not affected by different age correction methods. QTc-B was less affected by age, BMI and HR, although differences in sex should be noted.

A mouse zoonotic virus (LCMV): A possible candidate in the causation of SIDS

Lymphocytic choriomeningitis virus (LCMV) is a ubiquitous virus carried by rodents. It causes human disease through contact with infectious mouse faeces, urine or secretions. The virus initially infects the human respiratory tract and lungs and produces typical viral symptoms and signs. The infection is usually self-limiting and recovery is the norm. A small proportion of individuals may develop aseptic meningitis. It is hypothesised that in infancy the virus may cause respiratory tract infection through contact with mouse excreta. The infection could activate production of staphylococcal enterotoxin in babies who are colonised by Staphylococcus aureus. Indeed, a mouse animal model has shown that the combination of LCMV infection and introduction of enterotoxin B produces fatal haematogenous shock. Neither agent alone is lethal. Pathological (and physiological) evidence indicates shock could be the underlying terminal event in SIDS (the observed tissue damage seen in the heart and diaphragmatic muscles, and apoptosis observed in the brain and brainstem of SIDS cases). These features are consistent with a haematogenous shock event. The epidemiology of SIDS is entirely consistent with a mouse-related viral zoonosis. Moreover, rural cases of SIDS tend to feature more often than urban cases and their occurrence would be consistent with the dynamics of mouse populations. Low socioeconomic living conditions (a major risk factor for SIDS) is consistent with prevalence of mouse populations and poor hygienic conditions, with overcrowding. Prone sleeping would facilitate aspiration or ingestion of infectious material from contaminated surfaces. and poor hygienic conditions, with overcrowding, and prone sleeping would facilitate aspiration or ingestion of infectious material from contaminated surfaces. The epidemiology and pathology of SIDS and the dynamics and ubiquity of mouse populations together with human serological data would support the hypothesis that LCMV is a potential candidate as a key factor in the causation of SIDS.

Spatially varying effects of measured confounding variables on disease risk

BACKGROUND

The presence of considerable spatial variability in incidence intensity suggests that risk factors are unevenly distributed in space and influence the geographical disease incidence distribution and pattern. As most human common diseases that challenge investigators are complex traits and as more factors associated with increased risk are discovered, statistical spatial models are needed that investigate geographical variability in the association between disease incidence and confounding variables and evaluate spatially varying effects on disease risk related to known or suspected risk factors. Information on geography that we focus on is geographical disease clusters of peak incidence and paucity of incidence.

METHODS

We proposed and illustrated a statistical spatial model that incorporates information on known or hypothesized risk factors, previously detected geographical disease clusters of peak incidence and paucity of incidence, and their interactions as covariates into the framework of interaction regression models. The spatial scan statistic and the generalized map-based pattern recognition procedure that we recently developed were both considered for geographical disease cluster detection. The Freeman-Tukey transformation was applied to improve normality of distribution and approximately stabilize the variance in the model. We exemplified the proposed method by analyzing data on the spatial occurrence of sudden infant death syndrome (SIDS) with confounding variables of race and gender in North Carolina.

RESULTS

The analysis revealed the presence of spatial variability in the association between SIDS incidence and race. We differentiated spatial effects of race on SIDS incidence among previously detected geographical disease clusters of peak incidence and incidence paucity and areas outside the geographical disease clusters, determined by the spatial scan statistic and the generalized map-based pattern recognition procedure. Our analysis showed the absence of spatial association between SIDS incidence and gender.

CONCLUSION

The application to the SIDS incidence data demonstrates the ability of our proposed model to estimate spatially varying associations between disease incidence and confounding variables and distinguish spatially related risk factors from spatially constant ones, providing valuable inference for targeted environmental and epidemiological surveillance and management, risk stratification, and thorough etiologic studies of disease.

Sudden infant death syndrome prevention

We looked at existing recommendations and supporting evidence for successful strategies to prevent the sudden infant death syndrome (SIDS).

We conducted a literature search up to the 14th of December 2020 by using key terms and manual search in selected sources. We summarized the recommendations and the strength of the recommendation when and as reported by the authors. We summarized the main findings of systematic reviews with the certainty of the evidence as reported.

Current evidence supports statistical associations between risk factors and SIDS, but there is globally limited evidence by controlled studies assessing the effect of the social promotion strategies to prevent SIDS through knowledge, attitude and practices, due to obvious ethical reasons. A dramatic decline in SIDS incidence has been observed in many countries after the introduction of “Back to Sleep” campaigns for prevention of SIDS. All infants should be placed to sleep in a safe environment including supine position, a firm surface, no soft objects and loose bedding, no head covering, no overheating, and room-sharing without bed-sharing. Breastfeeding on demand and the use of pacifier during sleep time protect against SIDS and should be recommended. Parents should be advised against the use of tobacco, alcohol and illicit drugs during gestation and after birth.

What risk factors for sudden infant death syndrome are preterm and term medically complex infants exposed to at home?

OBJECTIVES

Risk factors for sudden infant death syndrome include premature birth, maternal smoking, prone or side sleeping position, sleeping with blankets, sharing a sleeping surface with an adult, and sleeping without an adult in the room. In this study, we compare parents' responses on sleep patterns in premature and term infants with medical complexity.

METHODS

Parents of children enrolled in the Canadian Respiratory Syncytial Virus Evaluation Study of Palivizumab were phoned monthly regarding their child's health status until the end of each respiratory syncytial virus season. Baseline data were obtained on patient demographics, medical history, and neonatal course. Responses on adherence to safe sleep recommendations were recorded as part of the assessment.

RESULTS

A total of 2,526 preterms and 670 term infants with medical complexity were enrolled. Statistically significant differences were found in maternal smoking rates between the two groups: 13.3% (preterm); 9.3% (term) infants (χ 2=8.1, df=1, P=0.004) and with respect to toys in the crib: 12.3% (term) versus 5.8% preterms (χ 2=24.5, df=1, P<0.0005). Preterm infants were also significantly more likely to be placed prone to sleep (8.8%), compared with term infants (3.3%), (χ 2=18.1, df=1, P<0.0005).

CONCLUSION

All the infants in this study had frequent medical contacts. There is a greater prevalence of some risk factors for sudden infant death syndrome in preterm infants compared to term infants with medical complexity. Specific educational interventions for vulnerable infants may be necessary.

Aquaporin 4 expression in the hippocampus in sudden infant death syndrome and sudden unexplained death in childhood

Aquaporin 4 (AQP4) is the main membrane water channel in the brain involved in regulating water homeostasis. The water distribution in neural tissue is often dysregulated after hypoxic neural injury. Previous research has indicated that victims of sudden infant death syndrome (SIDS) and sudden unexplained death in childhood (SUDC) have an underlying brain dysfunction that impairs their critical arousal response to hypoxic stress during sleep. The aim of this study was to determine the expression levels of AQP4 in the hippocampus in SIDS/SUDC cases and controls, and compare the findings with AQP4 genotypes that previously have been shown to be associated with SIDS. Immunochemical staining and morphometry were used to evaluate the density of AQP4-positive astrocytes in 30 SIDS/SUDC cases and 26 controls. AQP4-positive cells were counted in grids covering three layers in the hippocampus, which revealed that their count in any of the layers did not differ significantly between cases and controls. A decline in AQP4 expression was observed for infants older than 12 weeks. The AQP4 expression was lower in infants and children with the rs2075575 CT/TT genotype than in those with the CC genotype. This study indicates that AQP4 expression may be influenced by both age and genotype in infants. The role of AQP4 in the pathogenesis of SIDS remains to be elucidated.

Sudden infant death syndrome: deletions of glutathione-S-transferase genes M1 and T1 and tobacco smoke exposure

In developed countries, sudden infant death syndrome (SIDS) is the leading cause of death in infants in their first year of life. The risk of SIDS is increased if parents smoked during pregnancy and in presence of the child. Glutathione S-transferases (GSTs) catalyse the conjugation of glutathione with electrophilic compounds and toxins, making them less reactive and easier to excrete. As a gene dose effect was observed for GSTM1 and GSTT1, the aim of this study was to investigate whether there is a connection between homozygous or heterozygous gene deletions of GSTM1 or GSTT1 and the occurrence of SIDS. We found that heterozygous deletion of GSTM1 occurred significantly more frequently in the SIDS case group compared to the control group. A homozygous deletion of GSMT1 was slightly more frequently in the control group. A homozygous gene deletion of GSTT1 showed no significant difference between the SIDS group and the control group. We also found that in the SIDS group, the number of victims that were exposed to cigarette smoke was significantly higher than the number of victims without cigarette smoke exposure and that the mean lifetime of children whose mothers smoked was shorter in comparison with non-smoking mothers. In SIDS cases with homozygous gene deletions of GSTM1, the median life span of children with tobacco smoke exposure was 60 days shorter than without smoke exposure. In conclusion, the absence of these two genes is not the only trigger for SIDS but could be a critical aspect of SIDS aetiology, particularly in SIDS cases with smoking parents.

Association between monoamine oxidase A promoter polymorphism and the risk of sudden infant death syndrome: a meta-analysis

Introduction

The etiology of sudden infant death syndrome (SIDS) remains an unsolved problem. The aim of this meta-analysis is to investigate the potential association between monoamine oxidase A (MAOA) promoter variable number tandem repeat (VNTR) polymorphism and SIDS risk.

Methods

A systematic review and meta-analysis were conducted on studies from accessible electronic databases. Each VNTR variant was examined in each gender independently by comparing with the pooled results of other alleles.

Results

A total of six independent case–control studies including 1022 SIDS cases and 1839 controls were enrolled in this meta-analysis. In both of the whole populations and Caucasian populations, male infants with the low-MAOA-expression alleles (2R+3R) were found to exhibit a statistically significant increased risk of SIDS, whereas those with a 4R allele exhibited a reduced risk of SIDS. Besides, an increased risk of SIDS was detected in male Caucasian infants with 2R or 3R alleles. However, none of the allele or genotype variants was associated with SIDS in female victims.

Conclusion

In male Caucasian infants, the low expression of MAOA promoter VNTR alleles (2R and 3R) is associated with an increased risk of SIDS, and the existence of the 4R allele could be regarded as a protective factor.

Aquaporin-1 and aquaporin-9 gene variations in sudden infant death syndrome

Several studies have indicated that a vulnerability in the development and regulation of brain function is involved in sudden infant death syndrome (SIDS). The aim of this study was to investigate the genes encoding the brain aquaporins (AQPs) AQP1 and AQP9 in SIDS. The hypothesis was that specific variants of these genes are part of the genetic vulnerability predisposing infants to sudden unexpected death. The study included 168 SIDS cases with a median age of 15.5 (range 2–52) weeks and 372 adolescent/adult deceased controls with a median age of 44 (range 11–91) years. In the AQP1 gene, the rs17159702 CC/CT genotypes were found to be associated with SIDS (p = 0.02). In the AQP9 gene, the combination of a TT genotype of rs8042354, rs2292711 and rs13329178 was more frequent in SIDS cases than in controls (p = 0.03). In the SIDS group, an association was found between genetic variations in the AQP1 gene and maternal smoking and between the 3xTT combination in the AQP9 gene and being found lifeless in a prone position. In conclusion, this study adds further evidence to the involvement of brain aquaporins in SIDS, suggesting that specific variants of AQP genes constitute a genetic predisposition, making the infant vulnerable to sudden death together with external risk factors and probably other genetic factors.

Social network influences on new mothers' infant sleep adjustments

Despite public awareness campaigns, some parents continue to engage in infant sleep practices that are considered risky by health experts, such as bedsharing or placing their infants on their stomachs. This study examines the role their social networks play in shaping parents' responsiveness to new information and/or suggestions about how they should place their infants for sleep, paying attention to the respective effects of health professionals and their close interpersonal ties. We collected data from a sample of 323 new mothers in Washington, D.C., who described their infant sleep practices and perceived personal social networks. We find evidence that mothers' social networks play a significant role in the likelihood that they adjust their infant sleep practices within the first few months of their infants' lives. Mothers are more likely to change sleep practices when health professionals and/or (lay) family members advise them to do so. The influence of network members is not always positive. For mothers who initially follow safe practices, their probability of change increases if their network members substantially espouse unsafe practices. Among mothers with initially unsafe practices, network members' level of support for safe sleep practices is not predictive of the likelihood of sleep practice change. Implications for potential interventions are discussed.

Decreasing smoking during pregnancy: Potential economic benefit of reducing sudden unexpected infant death

Sudden Unexpected Infant Death (SUID) remains the leading cause of death among U.S. infants age 1-12 months. Extensive epidemiological evidence documents maternal prenatal cigarette smoking as a major risk factor for SUID, but leaves unclear whether quitting reduces risk. This Commentary draws attention to a report by Anderson et al. (Pediatrics. 2019, 143[4]) that represents a breakthrough on this question and uses their data on SUID risk reduction to delineate potential economic benefits. Using a five-year (2007-11) U.S. CDC Birth Cohort Linked Birth/Infant Death dataset, Anderson et al. demonstrated that compared to those who continued smoking, women who quit or reduced smoking by third trimester decreased the adjusted odds of SUID risk by 23% (95% CI, 13%-33%) and 12% (95% CI, 2%-21%), respectively. We applied these reductions to the U.S. Department of Health and Human Services' recommended value of a statistical life in 2020 ($10.1 million). Compared to continued smoking during pregnancy, the economic benefits per woman of quitting or reducing smoking are $4700 (95% CI $2700-$6800) and $2500 (95% CI, $400-$4300), respectively. While the U.S. obtained aggregate annual economic benefits of $0.58 (95% CI, 0.35-0.82) billion from pregnant women who quit or reduced smoking, it missed an additional $1.16 (95%CI 0.71-1.60) billion from the women who continued smoking. Delineating the health and economic impacts of decreasing smoking during pregnancy using large epidemiological studies like Anderson et al. is critically important for conducting meaningful economic analyses of the benefits-costs of developing more effective interventions for decreasing smoking during pregnancy.

Determining the prevalence of sudden and unexplained death in childhood (SUDC): a national Australian perspective

Sudden unexplained death in childhood (SUDC) is defined as the unexplained death of a child over the age of 12 months. The National Coronial Information System (NCIS) Australia was used to access data for deaths of children aged 1 to 4 years over the period 2010 to 2014. Cases were classified as those in which the cause of death was determined and those in which the child died suddenly and unexpectedly, and the cause of death remained undetermined. Categorical information was extracted for each case to determine risk factors associated with the cause of death. The overall rate of death in Australian children aged 1 to 4 years and for whom coronial data was available from 2010 to 2014 was 9.69/100,000 children. A cause of death was determined in 87% of cases with the average rate of death in this group being 8.49/100,000. Death remained undetermined in 13% of cases. The study determined that the SUDC rate in Australian children aged 1 to 4 years was 0.02/100,000. However, this rate may be as high as 0.40/100,000 children should further investigation be undertaken. These children tended to be 18-20 months of age and male, with death occurring primarily while prone during a sleep period in cooler months, thus having similar characteristics to sudden infant death syndrome.

Knowledge on sudden unexplained infant death-related safe sleep practices and infant cardiopulmonary resuscitation in pediatric nurses

PURPOSE

Sudden unexplained infant death (SUID) is a major contributor to infant mortality, and pediatric nurses have the responsibility to educate parents on SUID-reducing strategies. This study was conducted to measure pediatric nurses' knowledge of SUID-related safe sleep practices (K-SSSP) and infant cardiopulmonary resuscitation (K-ICPR).

METHODS

In total, 136 pediatric nurses were administered a survey including K-SSSP (13 items), K-ICPR (5 items), confidence in K-SSSP education (1 item; 5 points), and other factors relating to SUID experiences or education.

RESULTS

The correct answer rates of the K-SSSP and K-ICPR were 62.6% and 62.5%, retrospectively. The mean score for confidence in K-SSSP education was 2.6±0.9. Only 18 nurses (13.2%) responded that they educated parents on the content of the K-SSSP, while 76 nurses had received education on SUID. Positive relationships were observed between K-SSSP scores and higher education, between K-ICPR scores and having own child(ren) and clinical experience, and between confidence in K-SSSP education and higher education or having one's own child(ren). Nurses caring for newborns performed more SUID education than nurses working in other units.

CONCLUSION

There is a profound need to implement a systemic educational program on SUID and strategies to reduce SUID for pediatric nurses.

Post-mortem genetic investigation of cardiac disease-associated genes in sudden infant death syndrome (SIDS) cases

The sudden infant death syndrome (SIDS) is one of the leading causes of postneonatal infant death. It has been shown that there exists a complex relationship between SIDS and inherited cardiac disease. Next-generation sequencing and surveillance of cardiac channelopathy and cardiomyopathy genes represent an important tool for investigating the cause of death in SIDS cases. In the present study, targeted sequencing of 80 genes associated with genetic heart diseases in a cohort of 31 SIDS cases was performed. To determine the spectrum and prevalence of genetic heart disease associated mutations as a potential monogenic basis for SIDS, a stringent variant classification was applied and the percentage of rare (minor allele frequency ≤ 0.2%) and ultra-rare variants (minor allele frequency ≤ 0.005%) in these genes was assessed. With a minor allele frequency of ≤ 0.005%, about 20% of the SIDS cases exhibited a variant of uncertain significance (VUS), but in only 6% of these cases, gene variants proved to be “potentially informative.” The present study shows the importance of careful variant interpretation. Applying stringent criteria misinterpretations are avoided, as the results of genetic analyses may have an important impact of the family members involved.

International time trends in sudden unexpected infant death, 1969-2012

Background

Sudden unexpected infant death (SUID) - including sudden infant death syndrome (SIDS) - continues to be a major contributor to infant mortality worldwide. Our objective was to analyse time trends and to identify country-clusters.

Methods

The National Statistical Offices of 52 countries provided the number of deaths and live births (1969–2012). We calculated infant mortality rates per 1000 live births for SUID, SIDS, and all-cause mortality. Overall, 29 countries provided sufficient data for time course analyses of SUID. To sensitively model change over time, we smoothed the curves of mortality rates (1980–2010). We performed a hierarchical cluster analysis to identify clusters of time trends for SUID and SIDS, including all-cause infant mortality.

Results

All-cause infant mortality declined from 28.5 to 4.8 per 1000 live births (mean 12.4; 95% confidence interval 12.0–12.9) between 1969 and 2012. The cluster analysis revealed four country-clusters. Clusters 1 and 2 mostly contained countries showing the typical peak of SUID mortality during the 1980s. Cluster 1 had higher SUID mortality compared to cluster 2. All-cause infant mortality was low in both clusters but higher in cluster 1 compared to cluster 2. Clusters 3 and 4 had low rates of SUID without a peak during the 1980s. Cluster 3 had the highest all-cause infant mortality of all clusters. Cluster 4 had an intermediate all-cause infant mortality. The time trends of SUID and SIDS mortality were similar.

Conclusions

The country-specific time trends in SUID varied considerably. The identification of country-clusters may promote research into how changes in sleep position, smoking, immunisation, or other factors are related to our findings.

Hippocampal abnormalities and seizures: a 16-year single center review of sudden unexpected death in childhood, sudden unexpected death in epilepsy and SIDS

Sudden Unexpected Death in Childhood (SUDC) is the unexplained death of children aged between 1 and 18 years old. Hippocampal abnormalities have previously been described in Sudden Unexpected Death in Epilepsy (SUDEP) and it is possible that SUDC shares similar pathogenic mechanisms with SUDEP. Our aim was to determine the prevalence of hippocampal abnormalities, history of seizures and demographic features in our caseload of SUDC, SUDEP and SIDS cases. A review of post-mortem reports from 2003 to 2018 was carried out to identify cases of SUDC, SUDEP and SIDS. Histological evidence of hippocampal abnormalities, patient demographics (age, gender), sleeping position, and past medical history (history of seizures and illness 72 hours prior to death) were recorded. Statistical analysis was performed to compare the three groups. 48 SUDC, 18 SUDEP and 358 SIDS cases were identified. Hippocampal abnormalities associated with temporal lobe epilepsy were found in 44.4% of SUDC cases. 5/15 SUDC cases with a history of seizures demonstrated hippocampal abnormalities. SUDC cases were also more likely to be found prone compared to SIDS cases. In comparison with SIDS, both SUDC and SUDEP cases were more likely to demonstrate hippocampal abnormalities (SUDC: (OR = 9.4, 95% CI: 3.1-29.1, p < 0.001; SUDEP: OR = 35.4, 95% CI: 8.3-151.5, p < 0.001). We found a potential link between hippocampal abnormalities and epileptic seizures in SUDC. A concerted effort should be directed towards consistent sampling and standardized description of the hippocampus and clinical correlation with a history of seizures/epilepsy in postmortem reports.

[Smoking and Breastfeeding - CNGOF-SFT Expert Report and Guidelines on the management for Smoking Management During Pregnancy]

INTRODUCTION

The consequences of smoking have been studied more during pregnancy than during breastfeeding. There is a passage of nicotine and other substances in breast milk and some modifications of milk composition. The objectives of this chapter are to study the benefits of breastfeeding in women who smoke, and the adaptation of smoking, medication and behavioral habits in case of incomplete withdrawal to better guide women.

METHODS

The Medline database, the Cochrane Library and foreign guidelines from 1999 to 2019 have been consulted.

RESULTS

The conservation of the benefit of breastfeeding in smokers with regard to the prevention of respiratory infections, infantile colic, cognitive deficits, obesity, sudden infant death, is not known to date. It is therefore not recommended to include smoking status in the choice of feeding mode for the newborn (professional agreement). However, since breastfeeding is a factor associated with a reduction in smoking and/or withdrawal (NP2), it is recommended to promote breastfeeding in non-weaned women in order to limit smoking (grade B). The use of nicotine replacement therapy is possible during breastfeeding (professional agreement). In the absence of data, bupropion (Zyban®) and varenicline (Champix®) are not recommended for women who are breastfeeding (professional agreement). A free interval between smoking and breastfeeding reduces the concentration of nicotine in milk (NP4). For non-weaned women who are breastfeeding, it is therefore recommended not to smoke just before breastfeeding (professional agreement).

CONCLUSION

The results indicate that breastfeeding is possible in smokers, although less often initiated by them. If the conservation of its benefits for the child is not demonstrated to date, breastfeeding allows the mother to limit smoking.

[In Utero Exposure to Maternal Smoking: Impact on the Child from Birth to Adulthood - CNGOF-SFT Expert Report and Guidelines for Smoking Management during Pregnancy]

INTRODUCTION

Smoking during pregnancy leads to fetal passive smoking. It is associated with several obstetrical complications and is a major modifiable factor of maternal and fetal morbidity. Long-term consequences also exist but are less well known to health professionals and in the general population.

METHODS

Consultation of the Medline® database.

RESULTS

Maternal smoking during pregnancy is associated in the offspring with sudden infant death syndrome (NP2), impaired lung function (NP2), lower respiratory infections and asthma (NP2), overweight and obesity (NP2), cancers (NP3), risk of tobacco use, nicotine dependence and early smoking initiation (NP2). Unadjusted analyses show associations between in utero tobacco exposure and cognitive deficits (NP3), impaired school performance (NP3) and behavioral disorders in children (NP2), which are in a large part explained by environmental factors. There is a cross-generational effect of smoking during pregnancy. For example, an increased risk of asthma is observed in the grandchildren of smoking women (NP4). The respective roles of ante- and post-natal smoking remain difficult to assess.

CONCLUSION

These results highlight the importance of prevention measures against tobacco use in the general population, as well as screening measures and support for smoking cessation before or at the beginning of the pregnancy.

Pathology of unexpected sudden cardiac death: Obstructive sleep apnea is part of the challenge

Unexpected sudden cardiac death (SCD), sudden infant death syndrome (SIDS) and sudden intrauterine unexplained death (SIUD) are major unsolved, devastating forms of death that occur frequently. Obstructive sleep apnea (OSA) has been associated with increased cardiovascular and cerebrovascular morbidity and mortality, including sudden cardiac death (SCD). This editorial will review the pathology of SCD, including sudden infant death syndrome (SIDS) and sudden intrauterine unexplained death (SIUD); OSA with its cardiovascular consequences; the possible link between SCD and OSA, discussing the potential mechanisms underlying these two frequent, but yet overlooked pathologies. Finally, the possible preventive benefits of treating OSA and identifying patients at common risk for OSA and SCD and SIDS-SIUD to prevent unexpected deaths will be discussed. Post-mortem examination is of great importance in every case of SCD sine materia, with examination of the brainstem and cardiac conduction system on serial sections, when general autopsy fails, but it should be stressed that also the investigations of patients suffering from OSA should focus on the possibility of pathological findings in common with cases of SCD.

Take a deep breath and wake up: The protean role of serotonin preventing sudden death in infancy

Recordings from infants who died suddenly and unexpectedly demonstrate the occurrence of recurring apneas, ineffective gasping, and finally, failure to restore eupnea and arouse prior to death. Immunohistochemical and autoradiographic data demonstrate a constellation of serotonergic defects in the caudal raphe nuclei in infants who died of Sudden Infant Death Syndrome (SIDS). The purpose of this review is to synthesize what is known about adaptive responses of the infant to severely hypoxic conditions, which unleash a flood of neuromodulators that inhibit cardiorespiratory function, thermogenesis, and arousal and the emerging role of serotonin, which combats this cardiorespiratory inhibition to foster autoresuscitation, eupnea, and arousal to ensure survival following an hypoxic episode. The laryngeal and carotid body chemoreflexes are potent in newborns and infants, and both reflexes can induce apnea and bradycardia, which may be adaptive initially, but must be terminated if an infant is to survive. Serotonin has a unique ability to touch on each of the processes that may be required to recover from hypoxic reflex apnea: gasping, the restoration of heart rate and blood pressure, termination of apneas and, eventually, stimulation of eupnea and arousal. Recurrent apneic events, bradycardia, ineffective gasping and a failure to terminate apneas and restore eupnea are observed in animals harboring defects in the caudal serotonergic system models - all of these phenotypes are reminiscent of and compatible with the cardiorespiratory recordings made in infants who subsequently died of SIDS. The caudal serotonergic system provides an organized, multi-pronged defense against reflex cardiorespiratory inhibition and the hypoxia that accompanies prolonged apnea, bradycardia and hypotension, and any deficiency of caudal serotonergic function will increase the propensity for sudden unexplained infant death.

[Sudden infant death syndrome: Do the parents follow the recommendations?]

INTRODUCTION

Prone sleeping position is the main known modifiable risk factor for sudden infant death syndrome (SIDS). There are other SIDS recommendations although with less impact. The objective of this study is to describe the prevalence of prone position during sleep as well as other risk factors associated with SIDS in a sample of Spanish babies and infants.

METHODS

Cross-sectional study carried out on 640 families with children from 0 months to 11 months. In addition to the sleep position, the adherence to four other recommendations regarding SIDS was analysed: place where infant sleeps, breastfeeding, use of non-nutritive suction, and maternal smoking.

RESULTS

A total of 41.3% of infants under 6 months and 59.7% of infants aged 6 to 11 months slept in a non-recommended position. Only 6.4% of families analysed followed all five recommendations.

DISCUSSION

There is a high prevalence of modifiable risk factors for SIDS among the studied population. Personalized education should be promoted, along with other campaigns to raise awareness and prevent SIDS.

SIDS associated RYR2 p.Arg2267His variant may lack pathogenicity

Sudden infant death syndrome (SIDS) is the sudden death of an infant under 1 year of age that remains unexplained after death scene and medicolegal investigation, including a complete autopsy and clinical history review. The fatal event typically occurs during sleep and heart rhythm during the event is rarely documented. Large series which have utilized molecular autopsy show that long QT syndrome (LQTS) associated cardiac channel mutations contribute to between 5 and 10% of SIDS deaths. In addition, rare novel RYR2 variants have been identified in SIDS victims. Given the lack of a phenotype, the pathogenicity of these variants is inferred from in vitro studies. We report a family with 5 members (mother and 4 children) who are carriers of a rare RYR2 variant (c.6800G > A, p.Arg2267His [Exon: 45], heterozygous) which has previously been identified in a SIDS victim and shown to confer a gain-of-function CPVT phenotype in vitro. All of these 5 family members including the mother (age range 7 to 41 years) have had negative exercise stress tests, echocardiograms and Holter monitors. These findings suggest that caution should be exercised in inferring pathogenicity of rare RYR2 variants based on in vitro functional data which does not always translate to human phenotype.

Explaining sudden infant death with cardiac arrhythmias: Complete exon sequencing of nine cardiac arrhythmia genes in Dutch SIDS cases highlights new and known DNA variants

Previous studies suggested that Sudden Infant Death Syndrome (SIDS) can partially be genetically explained by cardiac arrhythmias; however, the number of individuals and populations investigated remain limited. We report the first SIDS study on cardiac arrhythmias genes from the Netherlands, a country with the lowest SIDS incidence likely due to parent education on awareness of environmental risk factors. By using targeted massively parallel sequencing (MPS) in 142 Dutch SIDS cases, we performed a complete exon screening of all 173 exons from 9 cardiac arrhythmias genes SCN5A, KCNQ1, KCNH2, KCNE1, KCNE2, CACNA1C, CAV3, ANK2 and KCNJ2 (∼34,000 base pairs), that were selected to harbour previously established SIDS-associated DNA variants. Motivated by the poor DNA quality from the paraffin embedded material used, the application of a conservative sequencing quality control protocol resulted in 102 SIDS cases surviving quality control. Amongst the 102 SIDS cases, we identified a total of 40 DNA variants in 8 cardiac arrhythmia genes found in 60 (58.8 %) cases. Statistical analyses using ancestry-adjusted reference population data and multiple test correction revealed that 13 (32.5 %) of the identified DNA variants in 6 cardiac arrhythmia genes were significantly associated with SIDS, which were observed in 15 (14.7 %) SIDS cases. These 13, and another three, DNA variants were classified as likely pathogenic for cardiac arrhythmias using the American College of Medical Genetics guidelines for interpretation of sequence variants. The 16 likely pathogenic DNA variants were found in 16 (15.7 %) SIDS cases, including i) 3 novel DNA variants not recorded in public databases ii) 7 known DNA variants for which significant SIDS association established here was previously unknown, and iii) 6 known DNA variants for which LQTS association was reported previously. By having replicated previously reported SIDS-associated DNA variants located in cardiac arrhythmia genes and by having highlighting novel SIDS-associated DNA variants in such genes, our findings provide additional empirical evidence for the partial genetic explanation of SIDS by cardiac arrhythmias. On a wider note, our study outcome stresses the need for routine post-mortem genetic screening of assumed SIDS cases, particularly for cardiac arrhythmia genes. When put in practise, it will allow preventing further sudden deaths (not only in infants) in the affected families, thereby allowing forensic molecular autopsy not only to provide answers on the cause of death, but moreover to save lives.

Concurrent prenatal drinking and smoking increases risk for SIDS: Safe Passage Study report

BACKGROUND

Sudden infant death syndrome (SIDS) is the leading cause of postneonatal mortality. Although the rate has plateaued, any unexpected death of an infant is a family tragedy thus finding causes and contributors to risk remains a major public health concern. The primary objective of this investigation was to determine patterns of drinking and smoking during pregnancy that increase risk of SIDS.

METHODS

The Safe Passage Study was a prospective, multi-center, observational study with 10,088 women, 11,892 pregnancies, and 12,029 fetuses, followed to 1-year post delivery. Subjects were from two sites in Cape Town, South Africa and five United States sites, including two American Indian Reservations. Group-based trajectory modeling was utilized to categorize patterns of drinking and smoking exposure during pregnancy.

FINDINGS

One-year outcome was ascertained in 94·2% infants, with 28 SIDS (2·43/1000) and 38 known causes of death (3·30/1000). The increase in relative risk for SIDS, adjusted for key demographic and clinical characteristics, was 11·79 (98·3% CI: 2·59-53·7, p < 0·001) in infants whose mothers reported both prenatal drinking and smoking beyond the first trimester, 3.95 (98·3% CI: 0·44-35·83, p = 0·14), for drinking only beyond the first trimester and 4·86 (95% CI: 0·97-24·27, p = 0·02) for smoking only beyond the first trimester as compared to those unexposed or reported quitting early in pregnancy.

INTERPRETATION

Infants prenatally exposed to both alcohol and cigarettes continuing beyond the first trimester have a substantially higher risk for SIDS compared to those unexposed, exposed to alcohol or cigarettes alone, or when mother reported quitting early in pregnancy. Given that prenatal drinking and smoking are modifiable risk factors, these results address a major global public health problem.

FUNDING

National Institute on Alcohol Abuse and Alcoholism, Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the National Institute on Deafness and Other Communication Disorders.

A standardized postmortem protocol to assess the real burden of sudden infant death syndrome

Sudden unexpected infant death (SUID) is a major cause of death in infants < 1 year of age. Sudden infant death syndrome (SIDS) is a SUID still unexplained after post-mortem examination. In 2014, a protocol of post-mortem investigation was introduced to assess both the prevalence and the etiopathogenesis of SUID. Our aim was to compare SUID data before and after the application of a standardized autopsy protocol of investigation. In the time interval 2004-2018, SUID cases occurring in the Veneto Region, North-East Italy, were referred to our Core Lab. Since 2014, a complete autopsy was performed, including gross and histological study with toxicologic and molecular analysis carried out at the referral center. A total of 36 SUIDs (22 M, mean age 95.5 ± 80 days), 17 before (group A) and 19 after (group B) 2014, were collected. In group A, only 1 (6%) resulted as explained SUID, due to lymphocytic myocarditis and 16 (94%) were SIDS. In group B, 8 were SIDS (42%) and 11 (58%) explained SUID cases (p < 0.01), consisting of interstitial pneumonia and bronchiolitis in 9 and lymphocytic myocarditis in 2 cases. Molecular analysis was positive for viruses in 8 of them (73%). In conclusion, since the application of a standardized protocol of post-mortem investigation, inflammatory, mostly infective, cardio-pulmonary diseases have been identified as the most common cause of SUID, with SIDS falling from 94 to 42% of SUID. Efforts must be made to implement a uniform autopsy protocol to provide reliable epidemiological data on SIDS.

Risk Factors for Sudden Infant Death Syndrome and Sleeping Practices in Korea

Sudden infant death syndrome (SIDS) in Korea remains a poorly-understood subject for both professionals and the public. Recent reports have emphasized ethnic differences in SIDS rates, suggesting that making adjustments in child-rearing practices may contribute substantially to SIDS reduction. Two of the three major risk factors for SIDS-vulnerability of the infant and exogenous factors-need to be understood in particular depth due to their broad scope and sociocultural grounding. This paper presents substantial issues regarding preterm birth and male gender on infants' vulnerability to SIDS in Korea. Practices of caring for healthy infants are addressed in the context of sleeping practices, including sleeping position, bedding arrangements, sleeping on the floor, the back-to-sleep position, high indoor temperatures and ondol floor heating, and swaddling. Professional and social awareness about how to reduce SIDS should be raised by promoting a better understanding of risk factors in the context of ethnic and cultural variations in child-rearing practices.

Knowledge assessment of sudden infant death syndrome risk factors in expectant mothers: A prospective monocentric descriptive study

In France, approximately 500 deaths per year are related to sudden infant death syndrome (SIDS). After a 75% reduction of SIDS-related deaths in the 1990s, thanks to large prevention campaigns directing parents to put their infants to sleep on their back, the number of SIDS-related deaths remains stable. However, we estimate that 100-200 infant deaths per year in France could be prevented with better education on the risk factors for SIDS. In this prospective, descriptive monocentric study, we aimed to evaluate the level of expectant women's knowledge about SIDS. Questionnaires were distributed during a midwife consultation. A score on sleeping conditions, environmental and protective factors was determined with coefficients attributed according to their relevance to SIDS. Of 296 questionnaires distributed, 202 were completed and included in the analysis from March 1 to September 21, 2018. Scores were distributed from 2 to 46/50. The average score was 28.6/50. Information was principally obtained from media and not health professionals. When the information was delivered by a caregiver, in particular by a paediatrician, we observed better knowledge among these women. This study shows that it is important for health professionals to take the time to inform future mothers about the risk factors for SIDS, especially the least informed population groups such as young mothers and those from lower socioeconomic status, in order to reduce the number of avoidable infant deaths.

Epidemiological survey in a day care center following toddler sudden death due to human metapneumovirus infection

We report the sudden death of a 33-month-old child owing to acute respiratory distress syndrome due to human metapneumovirus (hMPV) infection. Of 30 children attending the same day care centre, 26% and 59% had hMPV and multiple infections, respectively; three of six children with pneumonia had a diagnosis of hMPV. hMPV infection is common in childhood viral co-infections but it can cause sudden death.

The Impact of Health Messages on Maternal Decisions About Infant Sleep Position: A Randomized Controlled Trial

Sudden infant death syndrome (SIDS) rates in African-Americans are more than twice national rates, and historically, African-American parents are more likely than other groups to place infants prone, even when they are aware of supine sleep recommendations. Prior studies have shown African-Americans have low self-efficacy against SIDS but high self-efficacy against suffocation. This study aimed to determine the impact of a specific health message about suffocation prevention on African-American parental decisions regarding infant sleep position. We conducted a randomized controlled trial of 1194 African-American mothers, who were randomized to receive standard messages about safe sleep practices to reduce the risk of SIDS, or enhanced messages about safe sleep practices to prevent SIDS and suffocation. Mothers were interviewed about knowledge and attitude, self-efficacy and current infant care practices when infants were 2-3 weeks, 2-3 months and 5-6 months old. Analyses of covariance were conducted to estimate the change in knowledge, attitudes and practice in each group, and chi square tests were used to compare sleep position with each variable. Over the first 6 months, the proportion of African-American infants placed supine gradually decreased and was unchanged by enhanced education about SIDS, suffocation risk and sleep safety. While initially high self-efficacy against SIDS and suffocation correlated with supine positioning, by 5-6 months self-efficacy did not correspond to sleep position in either group.

Evaluation of a Crib Distribution and Safe Sleep Educational Program to Reduce Risk of Sleep-Related Infant Death

To increase access to safe infant sleep surfaces and reduce risk of sleep-related infant deaths, the Georgia Department of Public Health implemented a portable crib distribution and safe sleep educational program. The aim of this evaluation was to compare parental knowledge and practices related to infant sleep before and after receipt of the safe sleep educational program and crib. A prospective, matched pre- and post-test cohort design with a follow-up survey was utilized to evaluate changes in knowledge and practices. Female participants were recruited through the county health department and met the following criteria: (1) between 32 and 40 weeks pregnant or within 3 months postpartum, and (2) demonstrated financial need. Participants completed a survey prior to the start of a group educational program and upon program completion. For those who agreed, a follow-up phone survey was conducted approximately 10 weeks after program completion or after the infant's birth. McNemar's Chi square tests were conducted to detect significant differences between specific items on pre-test, post-test, and follow-up surveys, and paired sample t tests were conducted to compare differences in knowledge and practice scores. A total of 132 participants completed matched pre- and post-test surveys and 76 completed follow-up surveys. Knowledge of recommendations regarding position, surface, environment, smoking, breastfeeding, and pacifier use increased significantly between pre- and post-test, with most participants maintaining knowledge at follow-up. The proportion of recommended practices also increased significantly. A group-based safe sleep educational program can be effective in reducing risky infant sleep practices.

Sudden infant death as the most severe phenotype caused by genetic modulation in a family with atrial fibrillation

AIMS

To assess the functional impact of two combined KCNH2 variants involved in atrial fibrillation, syncope and sudden infant death syndrome.

METHODS AND RESULTS

Genetic testing of a 4-month old SIDS victim identified a rare missense heterozygous in KCNH2 variant (V483I) and a missense homozygous polymorphism (K897T) which is often described as a genetic modifier. Electrophysiological characterisation of heterologous HERG channels representing two different KCNH2 genotypes within the family, showed significant differences in both voltage and time dependence of activation and inactivation with a global gain-of-function effect of mutant versus wild type channels and, also, differences between both types of recombinant channels.

CONCLUSIONS

The rare variant V483I in combination with K897T produces a gain-of-function effect that represents a pathological substrate for atrial fibrillation, syncope and sudden infant death syndrome events in this family. Ascertaining the genotype-phenotype correlation of genetic variants is imperative for the correct assessment of genetic testing and counselling.

TRANSLATIONAL PERSPECTIVE

According to the current guidelines for clinical interpretation of sequence variants, functional studies are an essential tool for the ascertainment of variant pathogenicity. They are especially relevant in the context of sudden infant death syndrome and sudden cardiac death, where individuals cannot be clinically evaluated. The patch-clamp technique is a gold-standard for analysis of the biophysical mechanisms of ion channels.

Inconsistent classification of unexplained sudden deaths in infants and children hinders surveillance, prevention and research: recommendations from The 3rd International Congress on Sudden Infant and Child Death

This report details the proceedings and conclusions from the 3rd International Congress on Unexplained Deaths in Infants and Children, held November 26–27, 2018 at the Radcliffe Institute at Harvard University. The Congress was motivated by the increasing rejection of the diagnosis Sudden Infant Death Syndrome (SIDS) in the medical examiner community, leading to falsely depressed reported SIDS rates and undermining the validity and reliability of the diagnosis, which remains a leading cause of infant and child mortality. We describe the diagnostic shift away from SIDS and the practical issues contributing to it. The Congress was attended by major figures and opinion leaders in this area from countries significantly engaged in this problem. Four categories (International Classification of Diseases (ICD)-11 categories of MH11, MH12, MH14, PB00-PB0Z) were recommended for classification, and explicit definitions and guidance were provided for death certifiers. SIDS was reframed as unexplained sudden death in infancy or SIDS/MH11 to emphasize that either term signifies the lack of explanation following a rigorous investigation. A distinct category for children over the age of 1 was recommended (MH12). Definitions and exclusions were provided for the alternative categories of accidental asphyxia and undetermined. As recommended, unexplained sudden death in infancy or SIDS on a death certificate will code a unique, trackable entity, accurately reflecting the inability to determine a definitive explanation, while satisfying surveillance needs and reliable identification for research efforts. The conclusions will be submitted to the World Health Organization for inclusion in the upcoming ICD-11.

Role of fast inhibitory synaptic transmission in neonatal respiratory rhythmogenesis and pattern formation

Several studies have investigated the general role of chloride-based neurotransmission (GABA_A and glycinergic signaling) in respiratory rhythmogenesis and pattern formation. In several brain regions, developmental alterations in these signaling pathways have been shown to be mediated by changes in cation-chloride cotransporter (CC) expression. For instance, CC expression changes during the course of neonatal development in medullary respiratory nuclei and other brain/spinal cord regions in a manner which decreases the cellular import, and increases the export, of chloride ions, shifting reversal potentials for chloride to progressively more negative values with maturation. In slice preparations of the same, this is related to an excitatory-to-inhibitory shift of GABA_A- and glycinergic signaling. In medullary slices, GABA_A-/glycinergic signaling in the early neonatal period is excitatory, becoming inhibitory over time. Additionally, blockade of the Na⁺/K⁺/2Cl^- cotransporter, which imports these ions via secondary active transport, converts excitatory response to inhibitory ones. These effects have not yet been demonstrated at the individual respiratory-related neuron level to occur in intact (in vivo or in situ) animal preparations, which in contrast to slices, possess normal network connectivity and natural sources of tonic drive. Developmental changes in respiratory rhythm generating and pattern forming pontomedullary respiratory circuitry may contribute to critical periods, during which there exist increased risk for perinatal respiratory disturbances of central, obstructive, or hypoxia/hypercapnia-induced origin, including the sudden infant death syndrome. Thus, better characterizing the neurochemical maturation of the central respiratory network will enhance our understanding of these conditions, which will facilitate development of targeted therapies for respiratory disturbances in neonates and infants.

Monitoring of Chemical Risk Factors for Sudden Infant Death Syndrome (SIDS) by Hydroxyapatite-Graphene-MWCNT Composite-Based Sensors

Sensing properties of chemical sensors based on ternary hydroxyapatite-graphene-multiwalled carbon nanotube (HA-GN-MWCNT) nanocomposite in the detection of chemical substances representing risk factors for sudden infant death syndrome (SIDS), have been evaluated. Characterization data of the synthesized composite have shown that the graphene-MWCNT network serves as a matrix to uniformly disperse the hydroxyapatite nanoparticles and provide suitable electrical properties required for developing novel electrochemical and conductometric sensors. A HA-GN-MWCNT composite-modified glassy carbon electrode (HA-GN-MWCNT/GCE) has been fabricated and tested for the simultaneous monitoring of nicotine and caffeine by cyclic voltammetry (CV) and square wave voltammetry (SWV), whereas a HA-GN-MWCNT conductive gas sensor has been tested for the detection of CO2 in ambient air. Reported results suggest that the synergic combination of the chemical properties of HA and electrical/electrochemical characteristics of the mixed graphene-MWCNT network play a prominent role in enhancing the electrochemical and gas sensing behavior of the ternary HA-GN-MWCNT hybrid nanostructure. The high performances of the developed sensors make them suitable for monitoring unhealthy actions (e. g. smoking, drinking coffee) in breastfeeding women and environmental factors (bad air quality), which are associated with an enhanced risk for SIDS.

As easy as ABC: evaluation of safe sleep initiative on safe sleep compliance in a freestanding pediatric hospital

Background

The American Academy of Pediatrics (AAP) recommends the ABCs of safe infant sleep (alone, back, clear crib) to combat the increasing rates of Sudden Unexplained Infant Death (SUID). It is unclear if these recommendations are followed for infants hospitalized in pediatric facilities after the newborn period. The objectives of this study were to assess baseline infant sleep behaviors at a tertiary care freestanding pediatric hospital and to evaluate the effectiveness of a hospital-based infant safe sleep program in improving adherence to safe sleep recommendations.

Methods

A quality improvement program with pre- and post- analyses was performed on a convenience sample of infants < 12-months old utilizing a crib audit tool on two general pediatric inpatient units. The crib audit tool was used before and after the safe sleep program intervention. It recorded the infant's sleep position, location during sleep, and sleep environment. Interventions included: 1) nursing education, 2) crib cards with a checklist of the ABC's of safe sleep provided for the cribs of hospitalized infants, and 3) tracking boards to report weekly measured compliance with the ABCs. Chi square analysis was used to compare adherence to recommendations before and after program implementation.

Results

There were 62 cribs included pre-intervention and 90 cribs post-intervention. Overall, there was no significant change in safe sleep positioning (81% to 82%, p = 0.97). There was a significant increase in adherence to the safe sleep environment recommendation (3% to 38%, p < 0.01). Overall safe sleep, including both position and environment, referred to as ABC compliance, improved from 3% pre-intervention to 34% post-intervention (p < 0.01). Only 18% of cribs audited displayed a crib card, demonstrating poor compliance on placement of the cards. There was no significant difference in compliance with safe sleep recommendations between infants with a crib card compared to those without (25% vs. 37%, p = 0.51).

Conclusions

Significant improvements were made in sleep environments and overall safe sleep compliance after introduction of crib cards and tracking boards. Most likely the crib auditing process itself and the tracking boards had a larger impact than the crib cards.

Polymorphisms in the myeloid differentiation primary response 88 pathway do not explain low expression levels in sudden infant death syndrome

AIM

The aim of this study was to investigate if a range of known rare and common genetic variants in the Toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88) pathway were present or overrepresented in sudden infant death syndrome (SIDS) compared to controls.

METHODS

Genetic variations in the genes encoding TLR4, MyD88 and Interleukin-1 receptor-associated kinase 4 were analysed. The subjects investigated included 158 SIDS cases with a median age of 15.25 weeks (2-47 weeks), 80 cases of infectious death with a median age of 24.9 weeks (0-285 weeks) and 199 adult controls with a median age of 50 years (11-86 years). The cases were collected in the years 1988-2017, and the autopsies were performed at the Department of Forensic Sciences at Oslo University Hospital, Oslo, Norway.

RESULTS

The results showed that none of the genetic variants selected from the MyD88 pathway were associated with neither SIDS nor infectious death. Most of the rare genetic variants were homozygote for the common allele in all groups, while the rest revealed allelic variation.

CONCLUSION

The genetic variations investigated in this study did not appear to be involved in the pathogenesis of SIDS.

Is prone sleeping dangerous for neonates? Polysomnographic characteristics and NDN gene analysis

Objective:

Prone sleep is an identified risk factor for sudden infant death syndrome, possibly due to reduced blood pressure, cerebral oxygenation, and impaired cerebral vascular control. Cardiac and respiratory responses in neonates during supine and prone sleep have not been reported.

Materials and Methods:

In this study, daytime polysomnography (PSG) data from 17 neonates aged 2–3 days during supine and prone sleep were reported and the NDN gene, an important gene for neonatal respiratory control, was sequenced for correlation with neonatal respiratory parameters. Heart rate (HR), oxygen saturation, carbon dioxide concentration, sleep stages, central apnea index (CAI), obstructive apnea/hypopnea index (OAHI), and oxygen nadir were compared between supine and prone sleep and between participants with different single-nucleotide polymorphisms (SNPs) in the NDN gene.

Results:

During prone sleep, neonates had a faster HR, decreased oxygen saturation, and a longer duration of oxygen saturation <90% than during supine sleep, suggesting that cardiopulmonary responsiveness was impaired. Sleep efficiency, sleep stages, oxygen nadir, and carbon dioxide tension were not different during supine and prone sleep. Central apnea occurred more significantly than obstructive apnea. During supine and prone sleep, the CAI was 3.3 ± 2.9/h and 2.3 ± 2.6/h and the OAHI was 0.6 ± 0.7/h and 0.6 ± 0.8/h, respectively. We found one SNP rs3743340 in the NDN gene that had no effect on the sleep and respiratory parameters of PSG.

Conclusion:

Tachycardia and respiratory instability were recorded in neonates during prone sleep, suggesting that neonates are vulnerable to cardiopulmonary events during prone sleep. Therefore, young neonates should be kept in the supine sleep position unless there are contraindications.

Can we still do something-and what?-for a seemingly missing syndrome?

Background

Although several modifiable risk factors have been identified, and prone and side sleep positions were identified as preventing sudden infant death syndrome (SIDS), the epidemiology of sudden unexpected deaths in infancy (SUDI), which includes SIDS, has not unchanged in over a decade. What can be done?

Methods

Italian infant mortality rates were analysed between 1996 and 2015.

Results

Between 1996 and 2015 in Italy 1152 SUDI deaths were reported in infants less than one year old. SUDI decreased substantially from 18 in 1996 to 10.2 deaths per hundred live births in 2015 (− 43%), the contribution was the change in the SIDS rate from 11.3 to 4.1 (− 64%). However, since 1004 main and SIDS rates have not changed.

Conclusion

Interventions that support safe sleep must be maintained, but research is still needed since although these dramatic deaths have been reduced their causes remain unknown. The challenge is now to shift their trend which has been constant for too long.

Molecular mechanisms for nicotine intoxication

Nicotine, one of the more than 4700 ingredients in tobacco smoke, is a neurotoxin and once used as pesticides in agriculture. Although its use in agriculture is prohibited in many countries, nicotine intoxication is still a problem among the workers in tobacco farms, and young children as well as adults due to the accidental or suicidal ingestions of nicotine products. Understanding the mechanism of nicotine intoxication is important not only for the prevention and treatment but also for the appropriate regulatory approaches. Here, we review pharmacokinetics of nicotine and the molecular mechanisms for acute and chronic intoxication from nicotine that might be relevant to the central and the peripheral nervous system. We include green tobacco sickness, acute intoxication from popular nicotine products, circadian rhythm changes, chronic intoxication from nicotine through prenatal nicotine exposure, newborn behaviors, and sudden infant death syndrome.

The potential role of substance P in brainstem homeostatic control in the pathogenesis of sudden infant death syndrome (SIDS)

Victims of sudden infant death syndrome (SIDS) are believed to have an underlying dysfunction in medullary homeostatic control that impairs critical responses to life threatening challenges such as hypoxia, hypercarbia and asphyxia, often during a sleep period. This failure is thought to result from abnormalities in a network of neural pathways in the medulla oblongata that control respiration, chemosensitivity, autonomic function and arousal. Studies have mainly focused on the role of serotonin, 5-hydroxytyptamine (5HT), although the neuropeptide substance P (SP) has also been shown to play an integral role in the modulation of medullary homeostatic function, often in conjunction with 5-HT. Actions of SP include regulation of respiratory rhythm generation, integration of cardiovascular control, modulation of the baroreceptor reflex and mediation of the chemoreceptor reflex in response to hypoxia. Abnormalities in SP neurotransmission may, therefore, also play a significant role in homeostatic dysfunction of the neurotransmitter network in SIDS. This review focuses on the pathways within the medulla involving SP and its tachykinin NK1 receptor, their potential relationship with the medullary 5-HT system, and possible involvement in the pathogenesis of SIDS.